Egg shaped tyre

[naked_draughtsman]

Last night while out for a ride I noticed a regular bump bump bump as I was
riding along. I assumed that the wheel had gone out a true as I'd been
tinkering with it last weekend, although it had been perfect until
yesterday.

I've had a good look at it today and the wheel itself is truer than it's
ever been (it moves vertically by about 1mm at most and a bit less from side
to side) but there is a distinct flat spot in the tyre. To confirm, I
turned the tyre 90 degrees and the flat spot was 90 degrees away from where
I'd marked the previous flat spot on the rim. The tyre has a mould mark
which is roughly 5mm from the edge and is constant all the way round, but
when on the wheel it disappears under the rim at the flat spot.

The tyre is only a few weeks old, has only done 100 miles or so and the last
pair of the same type lasted about 2 years with no problems. Have I bought
a duff one? They came from Wiggle (as a pair, on special offer) - are
Wiggle any good for accepting returns? I'm not too keen on having to post 2
bike tyres back to them.

--
peter

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[John Wilton]

"naked_draughtsman" <[email protected]> wrote in message
news:[email protected]...
> Last night while out for a ride I noticed a regular bump bump bump as I
> was riding along. I assumed that the wheel had gone out a true as I'd
> been tinkering with it last weekend, although it had been perfect until
> yesterday.
>
> I've had a good look at it today and the wheel itself is truer than it's
> ever been (it moves vertically by about 1mm at most and a bit less from
> side to side) but there is a distinct flat spot in the tyre. To confirm,
> I turned the tyre 90 degrees and the flat spot was 90 degrees away from
> where I'd marked the previous flat spot on the rim. The tyre has a mould
> mark which is roughly 5mm from the edge and is constant all the way round,
> but when on the wheel it disappears under the rim at the flat spot.
>
> The tyre is only a few weeks old, has only done 100 miles or so and the
> last pair of the same type lasted about 2 years with no problems. Have I
> bought a duff one? They came from Wiggle (as a pair, on special offer) -
> are Wiggle any good for accepting returns? I'm not too keen on having to
> post 2 bike tyres back to them.
>
> --
> peter
>
> Cheap train tickets database
> http://www.petereverett.co.uk/tickets/
>
> Email sent to this address is generally deleted upon arrival
> Visit website if you want to contact me
>

I have had a similar sounding problem on some tyre/rim combinations caused
by the bead not seating correctly.

If this is the case try lubricating it (wax/soap ?) and taking it up to its
maximum pressure rating.

John

 

[Pete Biggs]

naked_draughtsman wrote:
> Last night while out for a ride I noticed a regular bump bump bump as
> I was riding along. I assumed that the wheel had gone out a true as
> I'd been tinkering with it last weekend, although it had been perfect
> until yesterday.
>
> I've had a good look at it today and the wheel itself is truer than
> it's ever been (it moves vertically by about 1mm at most and a bit
> less from side to side) but there is a distinct flat spot in the
> tyre. To confirm, I turned the tyre 90 degrees and the flat spot was
> 90 degrees away from where I'd marked the previous flat spot on the
> rim. The tyre has a mould mark which is roughly 5mm from the edge
> and is constant all the way round, but when on the wheel it
> disappears under the rim at the flat spot.
> The tyre is only a few weeks old, has only done 100 miles or so and
> the last pair of the same type lasted about 2 years with no problems.
> Have I bought a duff one?

Maybe.

> They came from Wiggle (as a pair, on
> special offer) - are Wiggle any good for accepting returns? I'm not
> too keen on having to post 2 bike tyres back to them.

This problem, in my experience, is usually caused by uneven seating and
usually solved by refitting the tyre. It can take several attempts. Try
over-inflating* (then letting down to usual pressure). I reckon this helps
push the tyre out.

Lube or talc is going to be suggested - but it's never worked for me.

* by as much as you dare, bearing in mind that rims can fail, or tyres can
pop off, if you go too far.

~PB

 

[peter-potato]

"Pete Biggs" <[email protected]> wrote in
message news:[email protected]...
> naked_draughtsman wrote:

> Lube or talc is going to be suggested - but it's never worked for me.

Talc is my preference, as it makes it smell much nicer...
Peter

 

[Peter Clinch]

naked_draughtsman wrote:

> I've had a good look at it today and the wheel itself is truer than it's
> ever been (it moves vertically by about 1mm at most and a bit less from side
> to side) but there is a distinct flat spot in the tyre. To confirm, I
> turned the tyre 90 degrees and the flat spot was 90 degrees away from where
> I'd marked the previous flat spot on the rim. The tyre has a mould mark
> which is roughly 5mm from the edge and is constant all the way round, but
> when on the wheel it disappears under the rim at the flat spot.

Either (a) it isn't seated properly or (b) is working its way to a
premature *Bang*. I speak from experience...

Deflate, reseat and reinflate, and if it's still there it's
probably (b) above.

> The tyre is only a few weeks old, has only done 100 miles or so and the last
> pair of the same type lasted about 2 years with no problems. Have I bought
> a duff one?

If it's not (a) then there's a good chance, I'd think. It does
happen (I speak from experience, got a free replacement)

> Wiggle any good for accepting returns?

There I can't help you...

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email protected] http://www.dundee.ac.uk/~pjclinch/

 

[Pete Biggs]

naked_draughtsman wrote:

> are Wiggle any good for accepting returns?

Yes, very good.

~PB

 

[Rob Morley]

In article <[email protected]>, naked_draughtsman
[email protected] says...
> Last night while out for a ride I noticed a regular bump bump bump as I was
> riding along. I assumed that the wheel had gone out a true as I'd been
> tinkering with it last weekend, although it had been perfect until
> yesterday.
>
> I've had a good look at it today and the wheel itself is truer than it's
> ever been (it moves vertically by about 1mm at most and a bit less from side
> to side) but there is a distinct flat spot in the tyre. To confirm, I
> turned the tyre 90 degrees and the flat spot was 90 degrees away from where
> I'd marked the previous flat spot on the rim. The tyre has a mould mark
> which is roughly 5mm from the edge and is constant all the way round, but
> when on the wheel it disappears under the rim at the flat spot.
>
Check that the bead isn't kinked on either side of the flat spot,
possibly where you used tyre levers before. If it is then remove the
kinks as best you can with your thumbs. Lubricate the bead with
washing-up liquid, refit the tyre and pump it up as hard as you dare,
checking occasionally that it's not going to blow off the rim (it's a
good idea to use eye and ear protection when doing this). Hopefully it
will pop back into place and you can then reduce the pressure to normal.

 

[naked_draughtsman]

"Rob Morley" <[email protected]> wrote in message
news:[email protected]...
> Lubricate the bead with
> washing-up liquid, refit the tyre and pump it up as hard as you dare,
> checking occasionally that it's not going to blow off the rim (it's a
> good idea to use eye and ear protection when doing this). Hopefully it
> will pop back into place and you can then reduce the pressure to normal.

Thanks for all your suggestions. I tried tried rubbing a few drops of
washing up liquid along the bead in the dodgy bit, pumped up to 80 psi but
didn't work, but possibly because the inner tube kept getting caught under
the tyre near the valve and popping the tyre off.

Spun tyre round so the tdodgy bit was over the valve and made sure the tube
was in properly, poured washing up liquid along the bead and gave it a bit
of a rub in. Pumped back up to 80 psi and it was fixed. The tyres say "max
100 psi" but don't give a minimum so I'll leave them at 80 psi for now and
will remember what to do next time it happens!

Thanks again

--
peter

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